1. Field of the Invention
The present invention is in the field of Silicon fabricated integrated circuits (ICs). More specifically, the present invention relates to Silicon fabricated ICs based on Silicon material grown epitaxially or bonded to Silicon Carbide (SiC) substrate in order to improve the heat dissipation of Silicon fabricated ICs while retaining the advantages of easiness of processing that the mature Silicon technology provides in order to compete with ICs fabricated on more exotic materials, such as Silicon Carbide.
2. Discussion of the Prior Art
In the prior art, there are various possibilities for growing and/or bonding Silicon Carbide (SiC) to Silicon (Si), however none for growing Silicon or bonding it to Silicon Carbide.
Nagasawa H. et al. in the paper entitled “3C—SiC Monocrystal Grown on Undulant Si (001) Substrates”, and published in Mat. Res. Soc. Symp. Proc., Vol. 742, on page 47, disclose the technique for growing SiC on Silicon substrates scrapped by diamond slurry and oxidized to promote undulations. According to Nagasaki technique, at first, a thin layer on the top surface of the “sacrificial” Silicon sample is carbonized to convert it to SiC. At the next step, an epi SiC layer of the desired thickness could be grown on top of the thin layer of SiC. The “sacrificial” Silicon sample is removed at the final step. This is the process used by the HOYA Advanced Semiconductor Technologies Company to produce SiC substrates up to 6 inches in diameter.
Another technique developed by the SOITEC company was described in the paper entitled “A New Process for the Fabrication of SiC Power Devices and Systems on SiCOI (Silicon Carbide On Insulator) Substrates”, and published by Templier, F. et al. in Mat. Res. Soc. Symp. Proc., Vol. 742, on page 395. The author of this technique used low cost polycrystalline SiC substrate.
The implementation and usage of all these prior art techniques depends significantly on mastering at least the following material technologies: (a) SiC large area substrate fabrication; and (b) SiC bonding techniques.
All these efforts are a result of the increased interest on building electronic devices on Silicon Carbide material as a result of it's very attractive and superior to Silicon electrical properties, However, the fact is that presently Silicon Carbide material technology has great challenges ahead in fabricating high purity, defect free substrates suitable for the manufacture of electronic circuits.
The present invention relates to new high performance active and passive structures that are built on Silicon material grown or bonded to Silicon Carbide substrates to leverage the Silicon mature technology with the excellent thermal dissipation of the Silicon Carbide substrates manufactured by one of the prior art processes described above or others. In the present invention the electrical quality of the Silicon Carbide substrate is of negligible importance and it can be single crystal or polycrystalline as long as it's thermal properties are substantial.